Expression pattern of CRYAB and CTGF genes in two pig breeds at different altitudes / [Padrão de expressão dos genes CRYAB e CTGF em duas raças de suínos em altitudes diferentes]

Tibetan pigs are characterized by significant phenotypic differences relative to lowland pigs. Our previous study demonstrated that the genes CRYAB and CTGF were differentially expressed in heart tissues between Tibetan (highland breed) and Yorkshire (lowland breed) pigs, indicating that they might participate in hypoxia adaptation. CRYAB (ɑB-crystallin) and CTGF (connective tissue growth factor) have also been reported to be associated with lung development. However, the expression patterns of CRYAB and CTGF in lung tissues at different altitudes and their genetic characterization are not well understood. In this study, qRT-PCR and western blot of lung tissue revealed higher CRYAB expression levels in highland and middle-highland Tibetan and Yorkshire pigs than in their lowland counterparts. With an increase in altitude, the expression level of CTGF increased in Tibetan pigs, whereas it decreased in Yorkshire pigs. Furthermore, two novel single-nucleotide polymorphism were identified in the 5' flanking region of CRYAB (g.39644482C>T and g.39644132T>C) and CTGF (g.31671748A>G and g.31671773T>G). The polymorphism may partially contribute to the differences in expression levels between groups at the same altitude. These findings provide novel insights into the high-altitude hypoxia adaptations of Tibetan pigs.

Porcos tibetanos são caracterizados por diferenças fenotípicas significativas em relação aos porcos de planície. Nosso estudo anterior demonstrou que os genes CRYAB e CTGF eram expressos diferentemente nos tecidos do coração entre os porcos tibetanos (raça das terras altas) e Yorkshire (raça das terras baixas), indicando que eles poderiam participar da adaptação à hipoxia. CRYAB (ɑB-crystallin) e CTGF (fator de crescimento do tecido conjuntivo) também foram relatados como estando associados ao desenvolvimento pulmonar. Entretanto, os padrões de expressão do CRYAB e CTGF nos tecidos pulmonares em diferentes altitudes e sua caracterização genética não são bem compreendidos. Neste estudo, o qRT-PCR e a mancha ocidental de tecido pulmonar revelou níveis de expressão de CRYAB mais elevados em porcos tibetanos e Yorkshire de altitude e média altitude do que em seus pares de planície. Com um aumento na altitude, o nível de expressão do CTGF aumentou nos porcos tibetanos, enquanto diminuiu nos porcos Yorkshire. Além disso, foram identificados dois novos polimorfismos de um único nucleotídeo na região flanqueadora de CRYAB (g.39644482C>T e g.39644132T>C) e CTGF (g.31671748A>G e g.31671773T>G). O polimorfismo pode contribuir parcialmente com as diferenças nos níveis de expressão entre grupos a uma mesma altitude. Estas descobertas proporcionam novos conhecimentos sobre as adaptações de hipoxia a alta altitude dos porcos tibetanos.

Net Energy Prediction Equations Used in Chinese Yellow Chickens for Energy Evaluation

ABSTRACT This study assessed whether the net energy (NE) system is beneficial for determining the efficiency of feed utilization in Chinese Yellow Chickens. A total of 5,600 male Chinese Yellow Chickens were assigned to eight dietary treatments (ten replicate pens per treatment and 70 chickens per pen) of differing apparent metabolizable energy (AME) and NE values. A highly significant linear correlation between dietary energy and feed conversion ratios (FCR) was observed (p 0.01). The linear regression equation between metabolizable energy (ME) and FCR was: AME=1435.5×F/G+6278.2, where R²=0.8272. The linear regression equation between NE and FCR was NE=1350.1×F/G+5340.9, and R²=0.9551. The R² of FCR (0.9551) for diets formulated using NE values was higher than the R² of FCR (0.8272) for diets prepared on the basis of the ME system. We conclude that the NE system is more accurate than the AME system for determining the energy requirements of Chinese Yellow Chickens.

Effects of dietary crude protein on the growth performance, carcass characteristics and serum biochemical indexes of Lueyang black-boned chickens from seven to twelve weeks of age

This study was undertaken to assess dietary crude protein (CP) concentration for optimum growth performance and carcass characteristics of Lueyang black-boned chicken. In total, six hundred 42-day-old Lueyang black-boned chicks were randomly assigned to five treatments, each with six replicate pens with ten males and ten females. The birds fed experimental diets with different levels of protein concentration of 120, 140, 160, 180 and 200 g kg-1 from seven to twelve weeks of age respectively. On day of 84, weight gain, feed intake, and feed:gain ratio were measured, and two chickens (one male and one female) close to the average weight of all birds in each treatment were selected from each pen and sacrificed to evaluate carcass traits and selected serum biochemical indexes. Dietary CP concentration did not have any significant influence on feed intake (p>0.05). The birds fed the diet with 180 or 160 g kg-1 CP concentration exhibited greater (p< 0.05) growth rate, better feed conversion ratio, relative breast weight and albumin concentration in serum than that of those fed other dietary CP concentrations. According to the results of regression analysis, the CP requirements of Lueyang black-boned chicken from seven to twelve weeks of age for optimal weight gain and feed:gain ratio were 174 and 170 g kg-1, respectively.

Effects of dietary crude protein on the growth performance, carcass characteristics and serum biochemical indexes of Lueyang black-boned chickens from seven to twelve weeks of age

This study was undertaken to assess dietary crude protein (CP) concentration for optimum growth performance and carcass characteristics of Lueyang black-boned chicken. In total, six hundred 42-day-old Lueyang black-boned chicks were randomly assigned to five treatments, each with six replicate pens with ten males and ten females. The birds fed experimental diets with different levels of protein concentration of 120, 140, 160, 180 and 200 g kg-1 from seven to twelve weeks of age respectively. On day of 84, weight gain, feed intake, and feed:gain ratio were measured, and two chickens (one male and one female) close to the average weight of all birds in each treatment were selected from each pen and sacrificed to evaluate carcass traits and selected serum biochemical indexes. Dietary CP concentration did not have any significant influence on feed intake (p>0.05). The birds fed the diet with 180 or 160 g kg-1 CP concentration exhibited greater (p< 0.05) growth rate, better feed conversion ratio, relative breast weight and albumin concentration in serum than that of those fed other dietary CP concentrations. According to the results of regression analysis, the CP requirements of Lueyang black-boned chicken from seven to twelve weeks of age for optimal weight gain and feed:gain ratio were 174 and 170 g kg-1, respectively.(AU)